fix(conference-scheduling): address remaining Copilot review findings

Unknown prerequisite talk codes now fail fast like every other reference,
the dataset info span is closed properly, a stray jQuery .fail() argument
is removed and DemoDataBuilderTest uses assertNull.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qae2bExuXdkKjDJjFXynGi

Author: larsbeck

use-cases/conference-scheduling/src/main/java/org/acme/conferencescheduling/service/ConferenceScheduleModelConvertor.java

@@ -193,8 +193,7 @@ private static void applyPrerequisites(List<TalkDTO> talkDtos, Map<String, Talk>
                 continue;
             }
             SequencedSet<Talk> prerequisites = dto.prerequisiteTalkCodes().stream()
-                    .map(talkMap::get)
-                    .filter(java.util.Objects::nonNull)
+                    .map(code -> require(talkMap, code, "prerequisite talk"))
                     .collect(toCollection(LinkedHashSet::new));
             talkMap.get(dto.code()).setPrerequisiteTalks(prerequisites);
         }

use-cases/conference-scheduling/src/main/resources/META-INF/resources/app.js

@@ -590,7 +590,7 @@ function analyze() {
             + " <b>Timefold Solver Enterprise Edition</b>, which is not on the classpath."
             + " If the latter, reach out to Timefold, obtain your license,"
             + " and then run the quickstart with an Enterprise profile to see Score analysis in action."));
-    }, "text");
+    });
 }
 
 function getScoreComponents(score) {

use-cases/conference-scheduling/src/main/resources/META-INF/resources/index.html

@@ -63,7 +63,7 @@
         <div class="sticky-top d-flex justify-content-center align-items-center" aria-live="polite" aria-atomic="true">
             <div id="notificationPanel" style="position: absolute; top: .5rem;"></div>
         </div>
-        <blockquote id="datasetInfo">Generate the optimal schedule for your conference talks. <span id="info" class="fw-bold"></blockquote>
+        <blockquote id="datasetInfo">Generate the optimal schedule for your conference talks. <span id="info" class="fw-bold"></span></blockquote>
 
         <div id="solveControls" class="mb-2">
             <button id="solveButton" type="button" class="btn btn-success">

use-cases/conference-scheduling/src/test/java/org/acme/conferencescheduling/demo/DemoDataBuilderTest.java

@@ -1,6 +1,7 @@
 package org.acme.conferencescheduling.demo;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import org.acme.conferencescheduling.dto.ConferenceScheduleInput;
@@ -19,8 +20,8 @@ void shouldBuildData() {
         assertEquals(15, problem.talks().size());
         problem.talks().forEach(talk -> {
             assertNotNull(talk.code());
-            assertEquals(null, talk.timeslotId());
-            assertEquals(null, talk.roomId());
+            assertNull(talk.timeslotId());
+            assertNull(talk.roomId());
         });
     }
 }